Mount Prospect, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

543
FXUS63 KLOT 062016
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
216 PM CST Fri Mar 6 2026

.KEY MESSAGES...

- Strong to severe thunderstorms with damaging winds and large
  hail are possible across northern Illinois through early
  evening, particularly around and south of Interstate 80.

- Another round of scattered thunderstorms may bring strong to
  locally damaging winds across the area late tonight through
  around sunrise Saturday.

- Chance for thunderstorms next Tuesday into Tuesday night.

&&

.MESOSCALE...
Issued at 143 PM CST Fri Mar 6 2026

A deep cold pool from this morning`s convection across northern
Illinois has become a focus for an effective warm front early
this afternoon. Latest analysis as of 1pm shows the front
situated from extreme southern La Salle County, to just north of
Kankakee to Valparaiso. While the northward progression of the
front has been quite slow over the past couple hours, clearing
skies should allow the front to gradually mix northward through
the remainder of the afternoon. South of the front, a shallow
cumulus field has developed, with some pockets of locally deeper
growth. A recent strong storm residing on the warm front near
Valparaiso combined with forecast guidance indicates that
surface based inhibition will remain weak through the remainder
of the day. So the main question revolves around when/if any
appreciable forcing will interact with the warm sector to
generate strong/severe convection over the next several hours.

Per satellite/radar trends since last evening, an elongated
ribbon of developing convection over west-central Illinois
appears to have emanated from a small convectively-induced wave
over western Oklahoma early this morning. Over the next few
hours, this cluster of convection should track ENE/NE over
northern Illinois, with the associated forcing possibly
overlapping the warm sector in/around the Illinois River Valley.
In this area, modest MLCAPE and increasing effective deep-layer
shear poses a decent risk for a cluster of organized severe
convection. Storm mode favors bowing segments with damaging wind
and perhaps some discrete and/or embedded supercells with
damaging wind and large hail. While veered surface flow will
limit the tornado risk, any discrete cell that crosses the front
will be capable of producing brief spin-ups.

North of the warm front, including into the Chicago metro, a
higher coverage of convection should remain mostly elevated.
This suggests the primary threat being large hail with discrete
cells and sub- severe gusty winds with any storm.

Kluber

&&

.DISCUSSION...
Issued at 216 PM CST Fri Mar 6 2026

See updated mesoscale discussion for information regarding
storms in the area through early evening.

An overall lull in precip is expected mid-evening into the
early overnight hours, a somewhat disorganized band of showers
and storms ahead of an approaching cold front is expected to
cross the area overnight into Saturday morning. With strong low-
level SW flow and a very moist airmass becoming anchored in the
warm sector through much of the night, low-level inhibition
should remain relatively weak ahead of any storms. With deeper-
layer forcing expected to remain somewhat disorganized,
convective mode lends toward broken linear segments as opposed
to a solid QLCS line. Either way, the relatively weak static
stability combined with an impressive kinematic field indicates
an inherent damaging wind risk with any storm.

The cold front will cross the forecast area through the day on
Saturday, with temperatures reaching the high in the morning
before steadily falling through the afternoon on breezy WNW
winds. Unseasonably warm conditions will persist Sunday and
Monday before a low passing well to the north pushes a cold
front over or through the area Monday night into Tuesday. A
trough ejecting from the southwest will interact with the
existing baroclinic zone somewhere over the region Tuesday into
Wednesday, bringing unsettled and cooler weather to the forecast
area during this time.

Kluber

&&

.AVIATION /18Z TAFS THROUGH 00Z SUNDAY/...
Issued at 1203 PM CST Fri Mar 6 2026

- Patchy MVFR/IFR in lingering SHRA early this afternoon,
  otherwise improvement to VFR.

- SSE winds turn S/SSW with some gusts 20-25 kts this afternoon.

- Spotty SHRA/isolated TS possible mid-afternoon into this
  evening, though coverage expected to be low w/o TAF mention
  for TS.

- Period of LLWS expected this evening/overnight.

- Additional waves of SHRA/TSRA late tonight into Saturday
  morning.

- Gusty SW winds 35-30 kt Saturday morning turn WNW in the
  afternoon.

A slow-moving surface low pressure system will lift northeast
from the central Plains across the northern/western Great Lakes
through Saturday. A warm front extending east from the low will
lift north across the terminals late today/this evening. Waves
of showers and thunderstorms (primarily this morning into early
this afternoon, and again late tonight into early Saturday) will
spread northeast across the terminals through early Saturday,
before a cold front pushes east across the area early Saturday
afternoon.

At midday, an area of SHRA/isolated TS continues to lift
northeast across the terminals, in association with a mid-level
disturbance (MCV) lifting into southern WI. Coverage of TS
coverage has already decreased markedly since this morning, and
SHRA are also expected to decrease in coverage by mid-afternoon.
Spotty SHRA/Isolated TS will remain possible from mid-afternoon
into early this evening, though coverage is anticipated to
remain low-enough to support mainly a VCSH mention in the TAFs.
Can`t rule out isolated TSRA at any particular terminal, but
will handle tactically heading into the afternoon/early evening.
TSRA and rain potential then is expected to increase across
MO/IA late this evening, and into northern IL after midnight.
Have maintained prevailing SHRA and prob30 TSRA mentions after
06/07Z as stronger large-scale forcing and a southwesterly 50 kt
low level jet develop. This period of higher precip coverage
looks to persist through/just beyond daybreak Saturday before
tapering off to drizzle/spotty light SHRA.

South-southeast winds across the terminals currently, will shift
southerly early this afternoon as the warm front south of the
I-80 corridor shifts northward. Winds may become a bit breezy
with gusts in the 20-25 kt range mid-late afternoon. South winds
should ease a bit with sunset, though the developing 50 kt SW
low level jet will support LLWS conditions from mid-evening into
the overnight hours. Surface gustiness returns late tonight and
persists into Saturday, with a peak in the 25-30 kt range
Saturday morning/early afternoon. Winds will shift WNW behind a
cold front early in the afternoon.

Ratzer

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...Dense Fog Advisory until 3 PM CST this afternoon for the IL
     nearshore waters.

&&

$$

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